The specific goals are to: a. Study the structure of the ovalbumin and globin genes in chromatin as model system to establish the nature of the structural changes that accompany transcriptional activation. b. Dissect the chromatin complex to determine factors that are responsible for the maintenance of an active conformation about the transcribing genes and to determine whether this configuration is both necessary and sufficient to permit transcription. c. Apply directly the technology developed in model systems to a study of the structure and the oncornavirus genes in chromatin. d. Examine the integration site of RNA tumor virus genomes in host cell DNA. BIBLIOGRAPHIC REFERENCES: Wigler, M. and Axel, R. (1976) Nucleosomes in Metaphase Chromosomes. Nucl. Acids Res. 3: 1463-1471. Wigler, M., Silverstein, S., Lee, L.-S., Pellicer, A., Cheng, Y.-C., and Axel, R. (1977) Transfer of Purified Herpes Virus Thymidine Kinase Gene to Cultured Mouse Cells. Cell, in press.